A location based service (LBS) is a service that determines a position of a user through a localization technique and provides various information or services based on the determined position of the user. Research into the location based service has been in active progress with the advent of smart phones having functions of a GPS, a terrestrial magnetic sensor, a camera, an RFID, or the like.
The location based service researched in the related art primarily relates to an outdoor localization system such as a localization technique using the GPS and a mobile communication network, a localization technique, or the like.
However, the outdoor localization system is not suitable in an indoor environment which requires accuracy estimation of location of the user. The reason is that accurate indoor localization is difficult due to influence of signal interference by an indoor structure such as a wall or the like indoors even though the outdoor localization system guarantees proper estimation of the location.
In order to solve the problem, Korean Patent Publication No. 2014-0055109 titled “Apparatus and Method for Identifying Location of Mobile Node” discloses a technology that detects a location of a mobile node by using information on a strength of a received signal transmitted from one or more reference nodes to a mobile node.
Further, Korean Patent Publication No. 2014-0066570 titled “System and Method for Navigation” discloses a technology that attaches a barcode including identification information to a predetermined point indoors and determines a location of a user in an indoor map by detecting the barcode.
As described above, various technologies for accurately detecting the location of the user positioned in a building are proposed.
However, since the location detection technology can determine only at which location the user is positioned in an indoor space and cannot determine in which direction the user views at the location.